Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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epoxy/polyethylene

Views: 933

#73244

epoxy/polyethylene | 18 December, 2014

Does anybody know what material is used for over molding I/Cs. I would like to find a material that others use to mold there electronic components. I am wire bonding and mounting a small cap (0201) on an FR-4 board. I need this material to withstand a temperature of 260c for ten seconds. This is to simulate a reflow oven or a wave solder machine after the parts are molded.

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#73246

epoxy/polyethylene | 18 December, 2014

I represent Epoxy Technology. They supply both epoxies and ployimides for this application. You reach their Applications Support group at (978) 667-3805. If you are located in the southeast you can also contact me.

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#73247

epoxy/polyethylene | 18 December, 2014

I have worked with Epoxy Technology in the past with silver epoxy. Just to fill you in on what I have been doing with this project in the past. I was using a silver epoxy for my 0201s. I then over molded with an epoxy with a dam and fill. Then they go to a dicing saw to be cut up, just like making an QFN package. What happens is the 0201 will break off of the board because of the different glass transition so now I'm using a solder to hold down my parts but the solder will re melt and causes shorts between all the die and caps. I then have gone to a 10/88/2 and a 11/90 solder to take care of that problem but I still need a material to handle the heat. I would like to use a injection mold to do this project because the over mold is messy and takes to long. I have heard of the polyimides for this process but have not found anybody that does what I'm trying to do. This is like pulling teeth to find anybody that does this type of work but I will call Epoxy Technologies back to see what they say.

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#73253

epoxy/polyethylene | 21 December, 2014

When I worked for a company that did alu-wire dice bonding they used a brand called Hysol for encapsuling. It needed heat cure. It's extremely hard to remove. As far as I remember it's epoxy based.

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Reflow Oven